App Development Company

21CN

Polish software and testing house building web and mobile apps and checking software quality for businesses

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About 21CN

Quality comes first at 21CN, a software and testing house in Poland that designs, builds and tests digital products. Software quality has been its focus since 2009, and quality is treated as the priority at each point in a product's life. Branding and staff hire are now also part of the firm's offer, together with IT services aimed at currency exchange offices.

Web and mobile applications

Web applications are shaped around a client's business objectives, and several are built on the Slim and Laravel frameworks. The mobile side is native apps for Android and iOS, designed for a smooth user experience and released as working products.

Testing, consulting and code audits

Quality assurance means testing for faults before a release and checking that software meets the relevant norms and standards. Consulting helps clients choose a technology stack and rework code so that a product can scale, and a code audit reviews what is already built before anything new is added.

Staff augmentation with developers and testers

Staff augmentation provides developers, testers, designers, project managers and quality engineers who join a client's team or replace it entirely. The firm says it can supply a single specialist or a whole team, scaling the team up or down as the client's needs change.

A portfolio that includes currency exchange

Among the studio's projects is a currency exchange platform showing live rates with online rate booking, plus a website, mobile app and admin panel for exchange offices. Other projects include a platform for a licensed property firm handling sales, rentals and management, an exam platform that tests IT specialists' practical skills through simulated scenarios, a knowledge portal for software testing services and a certification distribution platform. It has also built a family of education applications used in the TestingCup championship.

Brand identity beyond the logo

Brand identity covers more than a logo: naming, trademarks, colour palettes, graphic themes and the logo itself. The firm has built complete visual identities for a cafe and bistro in Gdańsk and a restaurant in the city's Nowy Port district. It also built an online store with a mobile app for a restaurant, used to accept and manage orders.

TrustList summary

21CN runs as a software and testing house that designs, builds and tests digital products. It has worked on software quality since 2009 and now also covers branding, staff hire and a dedicated line of IT services for currency exchange offices.

What 21CN does

Web applications: secure web apps built around a client's business goals, several on the Slim and Laravel frameworks.
Mobile applications: native apps for Android and iOS with attention to usability.
Quality assurance: testing to catch defects before release and to confirm software meets norms and standards.
Consulting and code audit: help choosing a technology stack and reworking code so a product can scale.
Staff augmentation: developers, testers, designers, project managers and QA engineers who join or replace a client's team, singly or as a whole team.
Brand identity: naming, trademarks, colour palettes, graphic themes and logos.

Customers and markets

Its portfolio includes a currency exchange platform with live rates and online rate booking, a site for a licensed property firm, exam and certification platforms for IT specialists, a software testing knowledge portal and brand identities for a café and a restaurant in Gdańsk.

Key facts

Working since: 2009
Specialism: websites, mobile apps and admin panels for currency exchange offices
Frameworks: Slim and Laravel

Summary written by TrustList from the business's own published information, Nov 2026.

Gallery

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Categories & features

21CN rankings

21CN is ranked on 7 TrustList rankings: #1 on 1, #3 on 1, #8 on 1, #12 on 1, #46 on 2 and #49 on 1.

Every ranking orders its listings by their reviews, how complete the profile is and the Trust Score. 21CN has no reviews yet and 3 of the 10 profile details we look for. Where no listing on a page has been reviewed, the order follows the profiles alone.

App development company · 7 rankings

#1of 23
Quality assurance
It is the only one of the 23 here listing code review and estimating.
Its profile: “Quality assurance means testing for faults before a release and checking that software meets the relevant norms and standards.”
Of the 23 here, 35 also cover android and 29 also cover eCommerce; 3 also work in London and 2 also work in Indore, India.
Behind Blue Rocket, ahead of KudosIntech Software Pvt. Ltd..
#3of 55
Laravel
It is the only one of the 55 here listing catering and quality assurance.
Its profile: “Web applications are shaped around a client's business objectives, and several are built on the Slim and Laravel frameworks.”
Of the 55 here, 50 also cover PHP and 41 also cover web development; 13 also work in Ahmedabad and 5 also work in Gujarat.
Behind Caxy Interactive.
#8of 136
Branding
It is the only one of the top 83 here listing jQuery and mobile development.
Its profile: “Branding and staff hire are now also part of the firm's offer, together with IT services aimed at currency exchange offices.”
Of the top 83 here, 30 also cover business services and 24 also cover creative; 5 also work in United States and 3 also work in Melbourne.
Behind Cuberto, ahead of 29 Digitals.
#12of 179
Sales
It is the only one of the top 88 here listing symfony and zend.
Of the top 88 here, 33 also cover information technology and 23 also cover financial services; 2 also work in Delhi NCR and 2 also work in Europe.
Behind LAYOUTindex, ahead of 5280 Software LLC.
#46of 1591
Business
It is one of 4 here listing DataBase and one of 7 here listing automation.
Its profile: “Web applications are shaped around a client's business objectives, and several are built on the Slim and Laravel frameworks.”
Of the top 98 here, 43 also cover mobile app development and 35 also cover iOS app; 5 also work in Rajasthan and 3 also work in Dubai.
Behind 20 Studio, ahead of 29 Digitals.
#46of 1429
Design
It is one of 5 here listing outsourcing and one of 7 here listing branding.
Of the top 94 here, 3 also work in Africa and 2 also work in San Francisco.
Behind 20tab, ahead of 24online.jo.
#49of 1543
It
It is one of 6 here listing laravel and one of 30 here listing PHP.
Its profile: “Branding and staff hire are now also part of the firm's offer, together with IT services aimed at currency exchange offices.”
Of the top 93 here, 4 also work in Jaipur and 3 also work in Silicon Valley.
Behind 2 Web, ahead of 29 Digitals.